NO

1 decompositions
 #1 -----------
   1: +(0(),x1) -> x1
   2: +(s(0()),x2) -> s(x2)
   3: +(s(s(x3)),x4) -> s(s(+(x4,x3)))
   4: +(x5,+(x6,x7)) -> +(+(x7,x6),x5)

unjoinable peak
    +(x20,x21)
*<- +(0(),+(x20,x21)) ->*
    +(+(x21,x20),0())